This invention relates to a guide bar for a chain saw.
Generally, a guide bar for a chain saw has been formed of a single plate or three plates bonded together into a laminate. Since a portable chain saw is operated by an operator who holds it by hand, it has been desired to reduce the weight of the body of a chain saw. When a guide bar is formed by working a single plate of a large thickness, it is time consuming and requires a lot of labor to effect machining of the thick plate. Moreover, the material cost and the working cost are high, so that the method of producing guide bars by working plates of a large thickness is not suitable for producing guide bars on a mass production basis. Also, in producing guide bars by bonding together three small thickness plates into a laminate, the method for working the three plates and bonding them is complicated and requires a large number of method steps to be followed. The method of producing guide bars by bonding three plates together into a laminate is more desirable than the method of producing guide bars each from a single plate of a large thickness. However, the guide bars in laminate form raise problems with regard to weight, working method and cost.